Portland State University this week unveiled a new outdoor student laboratory that doubles as a community park and features three experiments: green walls, green roofs and irrigation-free landscaping.

Four wood-framed living walls, created to test three companies' stormwater-catching techniques, jut from the Shattuck Hall Ecological Learning Plaza, which had its grand opening Tuesday at Southwest Broadway and College Street.

Plants vary by which direction a wall faces and include ginger, sword fern, winterberry, grasses and heather.

Solar panels power equipment inside the eight-foot walls, constantly measuring how much water each system holds and for how long. Readings are sent in real time to a computer in the office of Jeff Schnabel, assistant professor of architecture.

The project sparked four years ago when Schnabel discovered the university planned to raze the metal, 1960s-era Campus Public Safety Office building next to Shattuck Hall, which houses the Architecture Department. The university allowed him to transform the site into a student laboratory and university allocated $90,000 to the project.

Schnabel also reached out to the Metro regional government, which gave $65,000 for the green walls. The frame of the former public safety building, which Schnabel wanted intact, now supports the living walls.

Metro assisted with the walls because the agency is interested in this fairly new approach to "integrating nature and plantings into building construction," said Lisa Miles, Metro's principal development project manager. The data Schnabel collects will inform local builders, designers and developers on the costs and benefits of green walls, Miles said.

The project also benefited from "thousands and thousands of hours of volunteer time" from university students and the community, Schnabel said.

North of the green walls is the experiment that former plaza student representative Taryn Mudge spearheaded: the green roof.

The structure is a mock-up to test green roofs for a new Oregon Zoo building that architecture firm SRG Partnership Inc. is proposing. The goal is a steeper green roof requiring little irrigation. The roof has three rows. Plants in each row are the same, but they are grown in different materials and at different slopes.

Mudge, who earned her master's degree from the university this year, said the project taught her more than urban ecological systems. She also developed communication and leadership skills.

"I often found myself educating students, faculty and the public about our project throughout its development," said Mudge, who now works at SRG Partnership.

The third experiment, university plant specialist Keith Nevison's dueling gardens, lines the plaza's perimeter. The goal is to determine which uses water more efficiently: the native species or the drought-tolerant plants growing in the garden, Schnabel said.

The outdoor laboratory's real-world conditions make it a great place for experiments, which will be switched out every two years, Schnabel said.

The plaza also features hand-crafted cedar and metal benches, which students built and designed. Each has two wheels holding up one side and a pole on an axle propping up the other side, allowing the bench to rotate on its axle like a pencil compass. Visitors can swivel away from the sun or toward a friend seated nearby in the cobblestoned plaza, Schnabel said.

The cobblestones set in the plaza's pervious pavement may be more than 130 years old. Most are basalt that workers began mining in the Columbia River flood plain circa 1880, city documents show. The stones tiled city streets for decades.

In the 1970s, the city began extracting and stockpiling many of the stones. The city permits people to use the historical cobblestones only to pave large places with public access in areas of Portland once surfaced with the stones.

"Jeff Schnabel and PSU embraced the regulatory process, celebrated the history and have produced an incredible project," said Tim Heron, a senior city planner.

Architecture Department Chairman Clive Knights said Schnabel's project furthers his department's emphases: giving students practice using building materials, taking on topical urban issues and collaborating with community partners. The plaza is an attractive destination for the public and the campus community, Knights said.

"It's a great spot," he said, "for reading a book and drinking a cup of coffee."